1. Department
of Chemistry, Duke University, B120 Levine Science Research Center, Box 90317, Durham, North Carolina 27708, United States
2. Trinity College of Arts & Sciences, Duke University, Durham, North Carolina 27708, United States
3. Department
of Biochemistry, Duke University Medical Center, 255 Nanaline
H. Duke, Box 3711, Durham, North Carolina 27710, United States